1. Field of the Invention
The invention relates to paint compositions particularly semi-gloss and flat interior paint compositions. Latex paint compositions have captured a significant portion of the indoor and outdoor paint market because they have several advantages compared with the organic solvent type. Three significant advantages are: the paints offer an easy mechanism for clean up, there is substantially no air pollution and there is a reduced possibility of fire hazard. On the other hand, the coating properties and storage stability of the latex paints have been somewhat inferior to those of the solvent type, particularly in obtaining desired film thickness and obtaining good adhesion.
Two types of emulsions commonly used in formulating latex paints include the all acrylic system, e.g., the systems using copolymerized methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate with small proportions of acrylic acid, etc., as may be desired, and vinyl acetate formulations using vinyl acetate in combination with a small proportion of a lower alkyl acrylate, e.g., 2-ethylhexyl acrylate, methyl methacrylate, butyl acrylate, or dibutyl maleate. Heretofore, the all acrylic system has been used in premium quality paint as the emulsions have provided for good water resistance, desired leveling, film hardness, durability, scrubbability, etc.
Vinyl acetate-acrylic copolymer systems have been utilized in formulating interior flat, semi-gloss paints and exterior house paints. Vinyl acetate-butyl acrylate latices result in paint films with excellent toughness, scrub resistance and durability, while the vinyl acetate-dibutyl maleate emulsions have good abrasion resistance and flexibility as well as durability.
Wet adhesion, i.e., the quality of adhering to a previously painted, aged surface under wet or moist conditions, has been imparted to both acrylic systems and vinyl acetate systems by polymerizing a wet adhesion monomer into the copolymer.
Wet adhesion monomers generally have terminal olefinic unsaturation at one end and a terminal ureido group at the other end. U.S. Pat. Nos. 3,369,008, 3,366,613 and 2,727,019 disclose examples of such functional monomers.